Maternal condition, fecundity and oocyte quality of Argentine hake (Merluccius hubbsi) from the Northern stock

Abstract

The influence of the condition of spawning females on fecundity and oocyte quality, measured using morpho-physiological and biochemical indices, was analyzed for the Northern stock of Argentine hake (Merluccius hubbsi). First the relationships between morpho-physiological and biochemical indices were analyzed, and if they were influenced by female size. Samples of spawning-capable females were collected during the main reproductive peak of this stock in May 2011. The hepatosomatic index (HSI) in M. hubbsi was a good indicator of lipid concentration for both the liver and muscle. HSI and the relative condition factor (Kn) were independent of female size. Muscle protein content was positively associated with maternal attributes. Relative fecundity ranged between 287 and 916 hydrated oocytes g−1 and showed significant positive relationships with GSI and Kn. The dry weight of hydrated oocytes (n = 100) ranged between 2.65 and 4 mg and was positively related with the HSI. The oil droplet diameter of hydrated oocytes varied between 250 and 292 μm and was also positively related with HSI, Kn, liver and muscle lipid content, suggesting that it could be a good indicator of the nutritional condition for hake females of the Northern spawning stock.